topic Re: EVA 4100. Disk group extension in MSA Storage

EVA 4100. Disk group extension

Storage Network — Sat, 31 Jan 2009 14:10:00 GMT

Hello,

I have an EVA 4100 with one disk group with eight disk drives 300 GB FC, and other disk group witch eight disk drives 500 GB FATA.

I want to put six disk drive 1 FATA. What is the best practices. I extend second disk group with eight disk drives 500 GB FATA more six disk drive 1 TB FATA. I can do this ?

What is the best option ???

A lot of thanks.

Regards-

Re: EVA 4100. Disk group extension

Uwe Zessin — Sat, 31 Jan 2009 18:08:49 GMT

http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=1309649

Re: EVA 4100. Disk group extension

Storage Network — Sat, 31 Jan 2009 20:29:01 GMT

If i extend the second disk group i have eight disk drives 500 GB FC FATA and six disk drives 1 TB FC FATA, what is my total space for to creat Vdisks. I put single protection level.

What is my total space for create Vdisks ? I loss information from disk drives 1 TB FATA FC ????

A lot of thanks.

Best Regards.

Re: EVA 4100. Disk group extension

Sheldon Smith — Sun, 01 Feb 2009 07:16:46 GMT

(8 * 500 GB) + (6 * 1000 GB) - (2 * 1000 GB) = 4000 + 6000 - 2000 = 8000 GB _raw_ storage

Re: EVA 4100. Disk group extension

Storage Network — Sun, 01 Feb 2009 10:20:36 GMT

A lot of thanks for response.

Another question when i put one disk drive 1 TB FATA in Command View the disk have 931 GB.
Where the other 70 GB ? I loss this capactity ?

A lot of thank.

Regards

Re: EVA 4100. Disk group extension

Uwe Zessin — Sun, 01 Feb 2009 18:15:42 GMT

It is the difference between 'HardWare GigaBytes' and 'SoftWare GigaBytes' which I have just mention in the other thread:

http://forums.itrc.hp.com/service/forums/questionanswer.do?&threadId=1309649

There is no real 'loss' or, as some people claim 'overhead'.

The disk drive vendor multiplies the number of disk block with the size of a disk block (512 Byte) and devides it by 1,000,000,000 - the result printed on the disk drive is the 'HardWare GigaBytes'.

CV-EVA is computer software and devices by 1,073,741,824 (1024*1024*1024) - the result is 'SoftWare GigaBytes' (1024 = 2^10).

Again, there is no real difference, 'loss' or 'overhead' - just an invisible radix, like:

5 = 101 ?

5(10) = 101(2)
5(decimal) = 101(binary)

Test it yourself:
1,000,000,000,000 /1024/1024/1024 = ?